Synthesis of phosphinimide coordination compounds

ABSTRACT

Methods to make R 1   3 P═N—TiCl 3  and (1-R 2 -Indenyl)Ti(N═PR 1   3 )Cl 2 , where R 1  is independently selected from C 1-30  hydrocarbyl radical which is unsubstituted or further substituted by one or more halogen atom, a C 1-8  alkoxy radical, a C 6-10  aryl radical, a C 6-10  aryloxy radical, an amido radical, a silyl radical, and a germanyl radical; P is phosphorus; N is nitrogen (and bonds to the metal M); R 2  is a substituted or unsubstituted alkyl group, a substituted or an unsubstituted aryl group, or a substituted or unsubstituted benzyl group, wherein substituents for the alkyl, aryl or benzyl group are selected from alkyl, aryl, alkoxy, aryloxy, alkylaryl, arylalkyl and halide substituents. The method to make R 1   3 P═N—TiCl 3  combines a titanium species TiCl 3 (OR) where R is an alkyl or aromatic group, with a trimethylsilyl phosphinimide compound R 1   3 P═N—SiMe 3  in the presence of solvent, to give the titanium complex R 1   3 P═N—TiCl 3 . The method to make (1-R 2 -Indenyl)Ti(N═PR 1   3 )Cl 2  consists of deprotonating 1-R 2 -indene with an appropriate base, followed by reaction with R 1   3 P═N—TiCl 3 .

FIELD

Provided is an improved synthetic route to the titanium complexes R¹₃P═N—TiCl₃ and (1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂, where R¹ is independentlyselected from a C₁₋₃₀ hydrocarbyl radical which is unsubstituted orfurther substituted by one or more halogen atom, a C₁₋₈ alkoxy radical,a C₆₋₁₀ aryl radical, a C₆₋₁₀ aryloxy radical, an amido radical, a silylradical, and a germanyl radical. An R² group is a substituted orunsubstituted alkyl group, a substituted or an unsubstituted aryl group,or a substituted or unsubstituted benzyl group.

BACKGROUND

The identification of new and improved synthetic methods for makingcatalysts and catalyst precursors for use in highly activepolymerization catalysis is of importance to the polymer industry.

The known catalyst (1-C₆F₅CH₂-Indenyl)Ti(N═P(t-Bu)₃)Cl₂ has beensuccessfully employed as an active olefin polymerization catalyst (seeCA Patent Application Nos. 2,780,508 and 2,798,855). Previous methodsfor making catalysts of this general type, e.g., (1-R²-Indenyl)Ti(N═PR¹₃)Cl₂ where R¹ and R² are unsubstituted or substituted hydrocarbyl typegroups (see, for example, U.S. Patent Application No. 2006/0122054 andCA Patent Application Nos. 2,780,508 and 2,798,855) as well as methodsfor making important precursor molecules, although effective, aredifficult to scale up to a commercially significant scale.

SUMMARY

Provided is a method for making R¹ ₃P═N—TiCl₃, said method comprisingcombining TiCl₃(OR) with an approximately equimolar amount of R¹₃P═N—SiMe₃ in the presence of solvent, to give as reaction products theR¹ ₃P═N—TiCl₃ and RO—SiMe₃ wherein R¹ is independently selected from thegroup consisting of a C₁₋₃₀ hydrocarbyl radical which is unsubstitutedor further substituted by one or more halogen atoms, a C₁₋₈ alkoxyradical, a C₆₋₁₀ aryl radical, a C₆₋₁₀ aryloxy radical, an amidoradical, a silyl radical, and a germanyl radical; and wherein R is aprimary, secondary or tertiary alkyl group or an aromatic group.

Provided is a method for making (1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ comprisingthe following steps:

-   -   i) combining TiCl₃(OR) with an approximately equimolar amount of        R¹ ₃P═N—SiMe₃ to give R¹ ₃P═N—TiCl₃;    -   ii) combining a 1-substituted indene 1-R²—C₉H₇ with an        approximately equimolar amount of lithium di-isopropylamide to        give a 1-substituted indenide 1-R²—C₉H₆ anion;    -   iii) combining the 1-substituted indenide 1-R²—C₉H₆ anion with        the R¹ ₃P═N—TiCl₃ to give (1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂; wherein        R¹ is independently selected from a C₁₋₃₀ hydrocarbyl radical        which is unsubstituted or further substituted by one or more        halogen atoms, a C₁₋₈ alkoxy radical, a C₆₋₁₀ aryl radical, a        C₆₋₁₀ aryloxy radical, an amido radical, a silyl radical, and a        germanyl radical; R is a primary, secondary or tertiary alkyl        group or an aromatic group; and R² is a substituted or        unsubstituted alkyl group, a substituted or unsubstituted aryl        group, or a substituted or an unsubstituted benzyl group.

DETAILED DESCRIPTION

Other than in the operating examples or where otherwise indicated, allnumbers or expressions referring to quantities of ingredients, reactionconditions, etc. used in the specification and claims are to beunderstood as modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that can vary depending upon the desired properties,which the present invention desires to obtain. At the very least, andnot as an attempt to limit the application of the doctrine ofequivalents to the scope of the claims, each numerical parameter shouldat least be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical values, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between andincluding the recited minimum value of 1 and the recited maximum valueof 10; that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10. Because the disclosednumerical ranges are continuous, they include every value between theminimum and maximum values. Unless expressly indicated otherwise, thevarious numerical ranges specified in this application areapproximations.

All compositional ranges expressed herein are limited in total to and donot exceed 100 percent (volume percent or weight percent) in practice.Where multiple components can be present in a composition, the sum ofthe maximum amounts of each component can exceed 100 percent, with theunderstanding that, and as those skilled in the art readily understand,that the amounts of the components actually used will conform to themaximum of 100 percent.

Provided are new methods for synthesizing active polymerizationcatalysts as well as catalyst precursor compounds. The new methodseliminate the need for low temperature steps and avoid difficult andtime consuming filtration steps in order to obtain acceptable yields atlarge scales (e.g., at least about 400 mmol).

An indenyl ligand, “indenyl” or “Ind” as defined herein will haveframework carbon atoms with the numbering scheme provided below, so thelocation of a substituent can be readily identified.

An indenyl ligand is an anionic species and prior to coordination to asuitable metal center will typically exist as an indenide metal salt:for example a substituted or unsubstituted indenide salt of lithium.

In some embodiments, a phosphinimide ligand R¹ ₃P═N— is substituted onthe phosphorus atom (P) with three R¹ groups, which are independentlyselected from a C₁₋₃₀ hydrocarbyl radical which is unsubstituted orfurther substituted by one or more halogen atoms, a C₁₋₈ alkoxy radical,a C₆₋₁₀ aryl radical, a C₆₋₁₀ aryloxy radical, an amido radical, a silylradical, and a germanyl radical. A phosphinimide ligand is anionic andcoordinates to a suitable metal center (for example, Ti, Zr, Hf) throughthe nitrogen atom (N).

As used herein “hydrocarbyl” or “hydrocarbyl radical” refers to anorganic compound consisting entirely of hydrogen and carbon from whichone hydrogen atom has been removed allowing for a bond or link to formwith another compound, chemical group or atom. Aromatic hydrocarbons(arenes), alkanes, alkenes, cycloalkanes and alkyne-based compounds aredifferent types of hydrocarbons that, when one hydrogen is removed, formradicals including aryl, alkyl, alkenyl, cycloalkyl, and alkynyl.Hydrocarbyl radicals may be optionally substituted with additionalatoms, functional groups or radicals as described herein.

In some embodiments, a titanium compound R¹ ₃P═NTiCl-₃ which has aphosphinimide ligand in its coordination sphere is made using a newsynthetic route. The new synthetic method involves the use of atrichlorotitanium hydrocarbyloxide TiCl₃OR which, when reacted with atrimethylsilyl phosphinimide R¹ ₃P═N—SiMe₃ species, gives the desiredproduct R¹ ₃P═N—TiCl₃ in high yield at large scale. The fact that thisreaction works well at large scale (e.g., at least about 400 mmolscales) allows facile production of active phosphinimide ligated olefinpolymerization catalysts at a commercially relevant scale

Step 1: Preparation of TiCl₃(OR), Option A:

An alcohol ROH is combined with titanium tetrachloride (TiCl₄) in thepresence of a solvent, such as a hydrocarbon solvent, in approximatelyequimolar amounts. Note that an alcohol ROH can be pre-dried with asuitable drying agent, such as, for example, NaOEt followed bydistillation. In an embodiment, an aromatic solvent (e.g., toluene)solution of alcohol ROH is slowly added to an aromatic solvent (e.g.,toluene) solution of TiCl₄, to avoid a large exotherm and to allow forthe HCl gas produced to be vented carefully, and optionally neutralized.After the two reagents are combined and visible HCl evolution has ceased(or slowed), the reaction mixture may be heated to complete thereaction. For example, the reaction may be heated to about 100° C. ormore for at least about 15 minutes to complete the reaction.

In an embodiment, the alcohol ROH is added to TiCl₄ and not in thereverse order, so as to keep TiCl₄ in excess during the addition.

The R group of the alcohol can be any suitable hydrocarbyl group, suchas a primary, secondary or tertiary alkyl group or an aromatic group.The hydrocarbyl group R may itself be substituted further with one ormore alkyl, aromatic or halide groups.

In an embodiment, the alcohol ROH is a primary or a secondary alcoholwhere R is a primary or secondary alkyl group having 1 to 20 carbonatoms.

In an embodiment, the alcohol ROH is a primary alcohol where R is aprimary alkyl group having 1 to 10 carbon atoms. In an embodiment, thealcohol ROH is a primary alcohol where R is a methyl, ethyl, n-propyl,n-butyl, or n-pentyl. In an embodiment, the alcohol ROH is a primaryalcohol where R is ethyl, n-propyl, or n-butyl. In an embodiment, thealcohol ROH is ethanol (R=ethyl). Methanol (R=Me) may also be used asthe alcohol ROH in an embodiment.

In an embodiment, the alcohol ROH is a secondary alcohol where R is asecondary alkyl group having 3 to 21 carbon atoms. In an embodiment, thealcohol ROH is a secondary alcohol where R is iso-propyl, sec-butyl, orneo-pentyl. In an embodiment, the alcohol ROH is isopropanol(R=isopropyl).

A person skilled in the art will recognize that use of other suitablesolvents, reaction temperatures and reaction times may also be used andoptimized, and that such conditions are not limiting. Hence, thereaction time for Step 1, Option A is not specifically defined and willdepend on various factors such as the reaction scale, temperature,solvent choice, reagent concentration and the like. In addition, thereaction temperature for Step 1, Option A is not specifically definedand will depend on various factors such as the reaction scale, time,solvent choice, reagent concentration and the like.

In an embodiment, Step 1, Option A is carried out above ambient (room)temperature. In an embodiment, Step 1, Option A is carried out aboveabout 80° C. In an embodiment, Step 1, Option A is carried out aboveabout 100° C.

In an embodiment, the TiCl₃(OR) compound is formed in the presence of asuitable solvent such as but not limited to toluene or pentane, is notisolated and used directly in the next step (see Step 2 below).

In an embodiment, the TiCl₃(OR) compound is formed in the presence of asuitable solvent such as but not limited to toluene or pentane, and isisolated by solvent removal.

In an embodiment, Step 1, Option A is carried out at a scale of at leastabout 400 mmol, or at least about 500 mmol, or at least about 1 mol.

Step 1: Preparation of TiCl₃(OR), Option B.

Ti(OR)₄ is combined with TiCl₄ in the presence of a solvent, such as ahydrocarbon solvent, in an approximately 1:3 molar ratio, where R isdefined as above. In an embodiment, an aromatic solvent (e.g., toluene)solution of Ti(OR)₄ is slowly added to an aromatic solvent (e.g.,toluene) solution of TiCl₄.

In an embodiment, Ti(OR)₄ is added to TiCl₄ and not in the reverseorder, so as to keep TiCl₄ in excess during the addition.

A person skilled in the art will recognize that other suitable solvents,reaction temperatures and reaction times may also be used and optimized,and that such conditions are not limiting. Hence, the reaction time forStep 1, Option B is not specifically defined and will depend on variousfactors such as the reaction scale, temperature, solvent choice, reagentconcentration and the like. In addition, the reaction temperature forStep 1, Option B is not specifically defined and will depend on variousfactors such as the reaction scale, time, solvent choice, reagentconcentration and the like.

In an embodiment, Step 1, Option B is carried out above ambient (room)temperature. In an embodiment, Step 1, Option B is carried out aboveabout 80° C. In an embodiment, Step 1, Option B is carried out aboveabout 100° C.

In an embodiment, the TiCl₃(OR) compound is formed in the presence of asuitable solvent such as but not limited to toluene or pentane, is notisolated and used directly in the next step (see Step 2 below).

In an embodiment, the TiCl₃(OR) compound is formed in the presence of asuitable solvent such as but not limited to toluene or pentane, and isisolated by solvent removal.

In some embodiments, Step 1, Option B is carried out at a scale of atleast about 400 mmol, or at least about 500 mmol, or at least about 1mol.

Step 2: Preparation of R¹ ₃P═N—TiCl₃.

TiCl₃(OR) is combined with an approximately equimolar amount of R¹₃P═N—SiMe₃ in the presence of a suitable solvent. The R¹ ₃P═N—SiMe₃compound may be added directly, as a solid or as a solution in asuitable solvent such as but not limited to toluene. The TiCl₃(OR) maybe present in a suitable solvent such as but not limited to toluenebefore combination with R¹ ₃—P═N—SiMe₃. The R¹ ₃P═N—SiMe₃ may be addedslowly in batches. Following addition of R¹ ₃P═N—SiMe₃ the reactionmixture is heated to drive the reaction forward.

In an embodiment R¹ ₃P═N—SiMe₃ is added to TiCl₃(OR) and not in thereverse order, so as to keep TiCl₃(OR) in excess during the addition,although the opposite order of addition is also contemplated.

A person skilled in the art will recognize that other suitable solvents,reaction temperatures and reaction times may also be used and optimized,and that such conditions are not limiting. Hence, the reaction time forStep 2 is not specifically defined and will depend on various factorssuch as the reaction scale, temperature, solvent choice, reagentconcentration and the like. In addition, the reaction temperature forStep 2 is not specifically defined and will depend on various factorssuch as the reaction scale, time, solvent choice, reagent concentrationand the like.

In an embodiment, Step 2 is carried out above ambient (room)temperature. In an embodiment, the reaction mixture is stirred for atleast about 12 hours at a temperature of at least about 80° C. In anembodiment, the reaction mixture is stirred for at least about 6 hoursat a temperature of at least about 100° C. In an embodiment, thereaction mixture is stirred for at least about 6 hours at a temperatureof at least about 110° C.

Depending on the reaction solvent used, the product R¹ ₃P═N—TiCl₃ mayprecipitate from the reaction solution and so may be isolated byfiltration. For example, where R¹ is tert-butyl, the productprecipitates from a solution of toluene.

Cooling the reaction mixture may cause product R¹ ₃P═N—TiCl₃ toprecipitate from solution. If the product R¹ ₃P═N—TiCl₃ precipitates orcrystallizes from solution, the product can be isolated by filtrationand washed with suitable hydrocarbon solvents such as but not limited totoluene, pentane, heptane or mixtures thereof.

In an embodiment, R¹ is independently selected from a C₁₋₃₀ hydrocarbylradical which is unsubstituted or further substituted by one or morehalogen atoms, a C₁₋₂₀ alkyl radical, a C₁₋₈ alkoxy radical, a C₆₋₁₀aryl radical, a C₆₋₁₀ aryloxy radical, an amido radical, a silylradical, and a germanyl radical. In one embodiment, each R¹ is a C₁₋₂₀alkyl radical, a C₁₋₈ alkoxy radical, a C₆₋₁₀ aryl radical, a C₆₋₁₀aryloxy radical, an amido radical, a silyl radical, and a germanylradical. In one embodiment each R¹ is a C₁₋₂₀ alkyl radical. In oneembodiment, R¹ is selected from propyl, butyl, pentyl, hexyl and octyl.In one embodiment each R¹ group is a tertiary butyl group (t-butyl,t-Bu, tert-butyl, tert-Bu for short).

In an embodiment, where R¹ is tert-butyl, the t-Bu₃P═N—TiCl₃ product isprepared in greater than about 80% yield at over about 90% purity by ¹HNMR over Steps 1 and 2.

In an embodiment, where R¹ is tert-butyl, the t-Bu₃P═N—TiCl₃ product isprepared in greater than about 90% yield at over about 95% purity by ¹HNMR over Steps 1 and 2.

In embodiments, Step 2 is carried out at a scale of at least about 400mmol, or at least about 500 mmol, or at least about 1 mol.

Step 3: Deprotonation of R²-Indene, R²—C₉H₇.

This step involves the removal of a proton from an indene molecule, forexample, a 1-position substituted indene molecule. Although thedeprotonation of indene molecules, whether substituted or unsubstitutedis well known and can be carried out with a variety of suitable bases,we have found that the deprotonation of an indene molecule which bears apentafluorophenyl benzyl moiety (C₆F₅CH₂—) can be difficult, unlesscarried out with a suitably non-nucleophilic and/or encumbered base.

Accordingly, in one embodiment a substituted indene molecule isdeprotonated with a relatively non-nucleophilic sterically encumberedmetal amide salt (relative to, for example, n-butyllithium). Suchsuitable amide salts may be selected from metal salts in which the anionis selected from the group comprising diisopropylamide,2,2,6,6-tetramethylpiperidide, bis(trimethylsilyl)amide and the like.Metal cations can be any suitable cation such as lithium or sodium orpotassium (Li⁺, Na⁺ or K⁺).

Treatment of an indene molecule with a suitable base will provide anindenide metal salt. Such indenide anions are well known to be suitableligands for transition metals and are most often referred to as indenylligands.

In an embodiment, the base used to deprotonate a substituted indenemolecule is lithium diisopropyl amide (LDA) which has the formula[iso-Pr₂N][Li].

In an embodiment, the indene molecule will be singly substituted wherethe substituent is selected from a substituted or unsubstituted alkylgroup, a substituted or an unsubstituted aryl group, and a substitutedor unsubstituted benzyl (e.g., C₆H₅CH₂—) group. Suitable substituentsfor the alkyl, aryl or benzyl group may be selected from alkyl groups,aryl groups, alkoxy groups, aryloxy groups, alkylaryl groups (e.g., abenzyl group), arylalkyl groups and halide groups.

In an embodiment, the indene molecule will be a singly substitutedindene, R²-Indene, where the R² substituent is a substituted orunsubstituted alkyl group, a substituted or an unsubstituted aryl group,or a substituted or unsubstituted benzyl group. Suitable substituentsfor an R² alkyl, R² aryl or R² benzyl group may be selected from alkylgroups, aryl groups, alkoxy groups, aryloxy groups, alkylaryl groups(e.g., a benzyl group), arylalkyl groups and halide groups.

In an embodiment, the indene molecule will have at least a 1-positionsubstituent (1-R²) where the substituent R² is a substituted orunsubstituted alkyl group, a substituted or an unsubstituted aryl group,or a substituted or unsubstituted benzyl group. Suitable substituentsfor an R² alkyl, R² aryl or R² benzyl group may be selected from alkylgroups, aryl groups, alkoxy groups, aryloxy groups, alkylaryl groups(e.g., a benzyl group), arylalkyl groups and halide groups.

In an embodiment, the base used to deprotonate a 1-position substitutedindene molecule (1-R²-indene or 1-R²—C₉H₇) is lithium diisopropyl amide(LDA) which has the formula [iso-Pr₂N][Li].

In an embodiment, the deprotonation reaction takes place in the presenceof a suitable aromatic solvent such as toluene at ambient (room)temperature.

A person skilled in the art will recognize that other suitable solvents,various reaction temperatures and various reaction times may be used andoptimized, and that such conditions are not limiting. Hence, thereaction time for Step 3 is not specifically defined and will depend onvarious factors such as the reaction scale, temperature, solvent choice,reagent concentration and the like. In addition, the reactiontemperature for Step 3 is not specifically defined and will depend onvarious factors such as the reaction scale, time, solvent choice,reagent concentration and the like.

In an embodiment, the deprotonation reaction is carried out at ambient(room) temperature (as opposed to low temperatures such as those belowroom temperature or below about 0° C., or at or below about −30° C., orat or below about −40° C.).

In an embodiment, the indene molecule will be a singly substituted,1-R²-Indene where the substituent R² is in the 1-position of the indenemolecule and R² is a substituted or unsubstituted alkyl group, asubstituted or unsubstituted aryl group, or a substituted or anunsubstituted benzyl group. Suitable substituents for an R² alkyl, R²aryl or R² benzyl group may be selected from alkyl groups, aryl groups,alkoxy groups, aryloxy groups, alkylaryl groups (e.g., a benzyl group),arylalkyl groups and halide groups.

In an embodiment, the indene molecule will be singly substituted at the1 position, 1-R²-Indene, where the substituent R² is a (partially/fully)halide substituted alkyl group, a (partially/fully) halide substitutedbenzyl group, or a (partially/fully) halide substituted aryl group.

In an embodiment, the indene molecule will be singly substituted at the1 position, 1-R²-Indene, where the substituent R² is a (partially/fully)halide substituted benzyl group.

When present on an indene molecule, a benzyl group can be partially orfully substituted by halide atoms, for example, fluoride atoms. The arylgroup of the benzyl group may be a perfluorinated aryl group, a 2,6(i.e., ortho) fluoro substituted phenyl group, 2,4,6 (i.e., ortho/para)fluoro substituted phenyl group or a 2,3,5,6 (i.e., ortho/meta) fluorosubstituted phenyl group respectively. The benzyl group is, in anembodiment, located at the 1 position of the indene molecule.

In an embodiment, the indene molecule will be a singly substitutedindene, 1-R²-indene, where the substituent R² is a pentafluorobenzyl(C₆F₅CH₂—) group.

In an embodiment, 1-C₆F₅CH₂-indene (1-C₆F₅CH₂—C₉H₇) is deprotonated withLDA to give [Li][1-C₆F₅CH₂-indenide]([Li][1-C₆F₅CH₂—C₉H₆]).

In an embodiment, 1-C₆F₅CH₂-indene (1-C₆F₅CH₂—C₉H₇) is deprotonated withLDA at ambient (room) temperature in the presence of a suitable solventsuch as but not limited to toluene to give [Li][1-C₆F₅CH₂-indenide]([Li][1-C₆F₅CH₂—C₉H₆]).

In an embodiment, 1-C₆F₅CH₂-indene (1-C₆F₅CH₂—C₉H₇) is deprotonated withLDA at ambient (room) temperature in the presence of a suitable solventsuch as but not limited to toluene to give [Li][1-C₆F₅CH₂-indenide]([Li][1-C₆F₅CH₂—C₉H₆]) and the [Li][1-C₆F₅CH₂-indenide] solution is useddirectly in the next step (see Step 4 below).

In an embodiment, Step 3 is carried out at a scale of at least about 400mmol, or at least about 500 mmol, or at least about 1 mol.

In an embodiment, the R²-indenide metal salt is formed in the presenceof a suitable solvent such as but not limited to toluene, or an etherealsolvent, is not isolated, and used directly in the next step (see Step 4below).

In an embodiment, the 1-R²-indenide metal salt is formed in the presenceof a suitable solvent such as but not limited to toluene, or an etherealsolvent, is not isolated, and used directly in the next step (see Step 4below).

In an embodiment, the [Li][1-C₆F₅CH₂-indenide] salt is formed in thepresence of a suitable solvent such as but not limited to toluene, isnot isolated, and used directly in the next step (see Step 4 below).

Step 4: Metallation of a R²-Indenide Ligand.

An indenide salt [Li][R²-indenide] where R² is defined as above may beemployed as a ligand precursor, which on reaction with R¹ ₃P═N—TiCl₃where R¹ is defined as above, becomes ligated to a metal center (i.e., abond is formed between at least one atom, for example, a carbon atom, ofthe ligand and the metal). In one embodiment, the indenyl ligand willbond to the metal via a five carbon ring which is bonded to the metalvia eta-5 (or in some cases eta-3) bonding.

In an embodiment, [Li][R²-indenide] is reacted with a phosphinimideligated titanium metal chloride R¹ ₃P═N—TiCl₃ (prepared as above) togive a phosphinimide coordination compound (R²-Indenyl)Ti(N═PR¹ ₃)Cl₂.

In an embodiment, [Li][1-R² indenide] is reacted with a phosphinimideligated titanium metal chloride R¹ ₃P═N—TiCl₃ (prepared as above) togive a phosphinimide coordination compound (1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂.

In an embodiment, [Li][1-R² indenide] is added to a phosphinimideligated titanium metal chloride R¹ ₃P═N—TiCl₃ (prepared as above), andnot in the reverse order, to give a phosphinimide coordination compound(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂.

Coordination compounds of the type (1-R²-indenyl)(R¹ ₃P═N)TiCl₂ areknown to be suitable catalyst components for polymerizing ethylene,optionally with alpha-olefins, to make ethylene polymers or copolymers.

In an embodiment, the metallation reaction is carried out in toluene.

In an embodiment, the metallation reaction is carried out in hydrocarbonsolvent such as heptane.

In an embodiment, the metallation reaction is carried out at ambient(room) temperature, in a hydrocarbon solvent.

In an embodiment, the metallation reaction is carried out at elevatedtemperature, for example at about 40° C. to about 90° C. in ahydrocarbon solvent.

A person skilled in the art will recognize other suitable solvents,reactions temperatures and reaction times may also be used andoptimized, and that such conditions are not limiting. Hence, thereaction time for Step 4 is not specifically defined and will depend onvarious factors such as the reaction scale, temperature, solvent choice,reagent concentration and the like. In addition, the reactiontemperature for Step 4 is not specifically defined and will depend onvarious factors such as the reaction scale, time, solvent choice,reagent concentration and the like.

In an embodiment, Step 4 is carried out at a scale of at least about 400mmol, or at least about 500 mmol, or at least about 1 mol.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 70% yield at over about 80% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 75% yield at over about 85% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 80% yield at over about 90% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 85% yield at over about 90% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 90% yield at over about 95% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, where R¹ is tert-butyl, and R² is C₆F₅CH₂— the(1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂ product is prepared in greater than anabout 90% yield at over about 99% purity by ¹H NMR over Steps 3 and 4.

In an embodiment, R¹ is tert-butyl, and R² is C₆F₅CH₂, and Steps 1-4 areall carried out in a single solvent such as but not limited to toluene.

In an embodiment, R¹ is tert-butyl, and R² is C₆F₅CH₂, and Steps 1-4 areall independently carried out at temperatures which are at or aboveambient (room) temperature.

In an embodiment, R¹ is tert-butyl, and R² is C₆F₅CH₂, and Steps 1-4 areall carried out in toluene at temperatures which are at ambient (room)temperature or above.

Some embodiments of the invention will further be described by referenceto the following examples. The following examples are merelyillustrative and are not intended to be limiting. Unless otherwiseindicated, all percentages are by weight unless otherwise specified.

EXAMPLES General Conditions

All reactions involving air and or moisture sensitive compounds wereconducted under nitrogen using standard Schlenk techniques, or in aglovebox. Toluene, heptane and pentane were purified using the systemdescribed by Pangborn, Grubbs, et. al. in Pangborn, A. B; Giardello, M.A.; Grubbs, R. H; Rosen, R. K.; Timmers, F. J. Organometallics 1996, 15,1518. Tetrahydrofuran was purified by passing it through a column ofactivated alumina, and pentane and the other solvents were stored overactivated 4 Å sieves. All chemicals were purchased from Aldrich and usedwithout further purification. Deuterated solvents were purchased fromCIL (THF-d₈, toluene-d₈) and were stored over 4 Å sieves. NMR spectrawere recorded on Bruker spectrometer (400.1 MHz for ¹H, 162 MHz for ³¹P,376 MHz for ¹⁹F).

Preparation of Lithium Diisopropylamide (LDA). n-BuLi (1.6 M, 32 mmols,20 mL) was added to a pentane solution (˜150 mL) of diisopropylamineiPr₂NH (dried over mol sieves and distilled, 20 mmols, 3.24 g) at roomtemperature. No apparent heat generation was observed. The mixture wasstirred for 1 hour to produce a clear solution. Pentane was pumped awayunder vacuum. The product solidified during pentane removal and at thatpoint, evacuation was terminated allowing the product to furthercrystallize for 3 hours. The solid product lithium diisopropylamide,LiN(iPr₂) (LDA) was isolated by filtration, washed with pentane anddried under vacuum. The solid weighed 2.8 g.

Preparation of t-Bu₃P═NSiMe₃. This compound was prepared by reaction oftri tert-butylphosphine (t-Bu₃P) with trimethylsilylazide (Me₃SiN₂).Preparation of t-Bu₃P═N—SiMe₃ was reported in the following: Courtenay,S.; Ong, C. M.; Stephan, D. W. Organometallics, 2003, 22, 818-825.

Ti(OEt)₄ (where Et is short for ethyl) was purchased from commercialsources.

Part A: Preparation of t-Bu₃P═N—TiCl₃ Comparative Example 1

Preparation of t-Bu₃P═N—TiCl₃ from TiCl₄ at Small Scale (<5 mmol). TiCl₄(0.5 g, 2.63 mmols) was added to a toluene solution (40 mL) oftBu₃P═N—SiMe₃ (760 mg, 2.63 mmol) in a 100 mL Schlenk flask. The orangesolution was stirred at ambient (room) temperature for 7 hours. Noobvious reaction was observed as the color of the solution was stillorange. The solution was refluxed at 110° C. overnight. The orangesolution became almost colorless. The solvent was pumped off to givepure t-Bu₃P═N—TiCl₃ as crystalline solid in 100% yield (0.97 g. ¹H NMR,δ(toluene-d₈): 1.08 (d, J=14 Hz); ³¹P NMR, δ(toluene-d₈): 55.2 (s),chemical shift calibrated.

Comparative Example 2

Preparation of t-Bu₃P═N—TiCl₃ from TiCl₄ at Larger Scale (>25 mmol). Atoluene solution (30 mL) of tBu₃P═N—SiMe₃ (7.63 g, 26.3 mmol) was addedto TiCl₄ (5.0 g, 26.3 mmols) in toluene (20 mL). A dark red solutionformed. The total reaction volume was about 70 mL after rinsings wereadded to the 100 mL reaction flask. After being stirred at roomtemperature for 0.5 hours, the solution was heated to 110° C. After 16hours, the solution was still dark orange. The color of the solution waschecked at 24 hours and 36 hours. The dark orange color did notdisappear. The solution was pumped to remove toluene. The residue waswashed with cold toluene (about 0° C., 2×20 mL) and then pentane (2×20mL). 1.8 g of pure product was isolated. The yield was only 18.4%.

By examining the yields of t-Bu₃P═NTiCl₃ obtained in Comp. Examples 1and 2, it is apparent that the yield is heavily diminished as the scaleof the reaction is increased. Without wishing to be bound by theory, itis believed that the above reaction is catalyzed by adventitious water,and that as the reaction scale increases, the relative amount of wateravailable to catalyze the reaction decreases, leading to a lower yield.

Comparative Example 3a

Preparation of t-Bu₃P═N—TiCl₃ in the presence of deliberately addedwater. Comp. Example 2 was repeated with the exception that 110 mg ofAl₂(SO₄)₃.18H₂O was added to the reaction after the two reactants weremixed. The solution was then heated to 115° C. and the reaction wasstirred overnight. A brown solution with an insoluble solid wasgenerated. The reaction was filtered while still hot. The filtration wasvery difficult as some of the product t-Bu₃P═N—TiCl₃ (which has poorsolubility in toluene) crystallized in the pores of the filter frit. Theinsoluble solid was rinsed with hot toluene (˜20 mL), then pentane (2×10mL) and was discarded (1.98 g). The filtrate and the hot washings werepumped to about 15 mL (while a lot of solid crystallized) and werechilled in a freezer overnight. The mother liquor was decanted. Thesolid was washed with pentane and dried under vacuum. The yield was 6.9g of beige solid (71%) and the product was pure by NMR.

Comparative Example 3b

Comparative example 3a was repeated under the same reaction conditionsand same reaction scale. With very difficult hot filtration, thereaction produced 3.1 g of greenish insoluble by-product and 5.4 g ofimpure product.

Comparative Example 4

Preparation of t-Bu₃P═N—TiCl₃ in the presence of added t-Bu₃P═NH andwater at larger scale (ca. 200 mmol). TiCl₄ (39.62 g, 208.8 mmols, in200 mL of toluene) was added to a dried toluene solution oft-Bu₃P═NSiMe₃ (100 g solution, 55 weight % (wt %), 55 g, 190 mmols). Thecolor of the mixture became brown. Toluene was added so that the totalvolume of the solution was made to about 400 mL. t-Bu₃P═NH (4.1 g, 18.86mmols, which was thought to accelerate the reaction) was added to takethe total amount of ligand to 208.86 mmols. The reaction was stirredwhile the heating bath temperature was raised to 115° C. Lots of solidprecipitated. Within 1.5 hours, the reaction turned to dark red withonly a very small amount of solid present. The reaction was heatedovernight to produce a slurry (insoluble solid was present). The colorof the reaction was still red indicating that the reaction wasincomplete. Al₂(SO₄)₃.18H₂O (354 mg) was slowly added over a 3 hourperiod. The color of the reaction changed from red to brown. The hotreaction mixture was filtered in order to remove the insoluble brownsolid. The filtration was very difficult as the product crystallizedvery easily from the hot solution and it began to plug the glass filterfrit. Hot toluene had to be used several times to rinse the glass fritand to keep the filtration going. The insoluble brown solid over thefrit was discarded. The light brown filtrate (with crystallized product)was cooled to ambient (room) temperature and chilled at −20° C. for 5hours. The solid was isolated by filtration and was washed withtoluene/heptane (50/50, 100 mL) and was dried under vacuum. The yieldwas 34.24 g (44%) and the product was pure by NMR.

By examining the yield and purity of the product t-Bu₃P═N—TiCl₃ as wellas the filtration difficulty for the procedures given in Comp. Examples3 and 4 it is apparent that the yield and purity can be poor for largerscale reactions and that the filtration to remove impurities isdifficult and time consuming.

Inventive Example 1

Preparation of t-Bu₃P═N—TiCl₃ from TiCl₃(OEt), Procedure 1 (ca. 180mmol). Preparation of TiCl₃(OEt). EtOH (dried with NaOEt and distilled,8.25 g, 179.07 mmol) in toluene (˜50 mL in a vial) was added to atoluene solution (100 mL) of TiCl₄ (33.97 g, 179.07 mmol) slowly at roomtemperature. The slow rate of addition was carefully controlled to avoida large exotherm and to slowly vent the HCl gas formed to a bubbler.After the addition, the vial containing the EtOH was rinsed with toluene(2×10 mL) and the rising were added to the reaction flask. The reactionmixture was then heated to 100° C. for 45 mins to drive off anyremaining HCl and to complete the reaction. The color of the solutionchanged from red to light orange. Preparation of t-Bu₃P═N—TiCl₃. In aglove box, solid t-Bu₃P═N—SiMe₃ (51.84 g, 179.07 mmol) was added inbatches, each over a 20 minute period, to the TiCl₃(OEt) solutionobtained above and which had been allowed to cool to room temperature.The solution became dark red. The reaction was stirred and heated at110° C. overnight. Crystalline product precipitated during the reaction.The content of the reaction was cooled to RT and chilled at −20° C. for3 hours. The solid was isolated by filtration and was washed with a50/50 toluene/heptane mixture (2×30 mL), then pentane (30 mL), and driedunder vacuum. ¹H and ³¹P NMR indicated that the product was pure. Theyield was 57 g (86%). ¹H NMR, δ(toluene-d₈): 1.11 (d, J=14 Hz); ³¹P NMR,δ(toluene-d₈): 55.3 (s), chemical shift calibrated. It is recommendedthat for procedure 1, the formation of TiCl₃(OEt) is driven tocompletion by heat and enough reaction time before the addition oft-Bu₃P═NSiMe₃.

A person skilled in the art will immediately recognize by comparing Inv.Example 1, with Comp. Examples 1-4, that use of TiCl₃(OEt) in place ofTiCl₄ provides the desired product t-Bu₃P═N—TiCl₃ in higher yield andhigher purity even at an ca. 180 mmol scale.

Verification:

The above reactions were repeated by a second experimenter at a scale of46 mmol. The solution which was formed by adding EtOH to TiCl₄ washeated at 100° C. for 30 minutes and cooled to room temperature. Thet-Bu₃P═N—SiMe₃ was added as a toluene solution to the TiCl₃(OEt) intoluene. The yield was 87% and the product was pure by ¹H and ³¹P NMR.

Alternative Solvent for TiCl₃(OEt) Formation:

To form TiCl₃(OEt) in pentane EtOH was added to a pre-sealed vial. Theweight of EtOH added was 2.294 g (49.8 mmol). Pentane (˜20 mL) was thenadded to the vial to make an EtOH solution. This solution was addedslowly to a pentane solution (˜50 mL) of TiCl₄ (9.45 g, 49.8 mmol) in a250 mL Schlenk flask. After the addition, pentane was pumped off to givesolid TiCl₃(OEt). Solid t-Bu₃P═N—SiMe₃ (14.3 g, 49.5 mmol) was added tothe flask and toluene (˜60 mL) was added. This solution was red incolor, and was refluxed overnight. The solution was chilled in thefreezer (−20° C.) for 2 hours, and a precipitated solid was isolated byfiltration and washed with toluene/heptane (50/50) (2×60 mL), then withpentane and dried. The yield was 15.9 g, 87% and the product was pure by¹H and ³¹P NMR.

Inventive Example 2

Preparation of t-Bu₃P═N—TiCl₃ from TiCl₃(OEt). Procedure 2. Preparationof TiCl₃(OEt). In a fume hood, Ti(OEt)₄ (5.703 g 25 mmols) was added toa toluene (60 mL) solution of TiCl₄ (14.228 g, 75 mmol). The brightorange solution turned light orange. The mixture was heated at 100° C.for 1.5 hours and cooled to room temperature. The flask was brought intoa glove box for the next step. Preparation of t-Bu₃P═N—TiCl₃.t-Bu₃P═N—SiMe₃ (28.95 g, 100 mmol) in toluene (˜100 mL) was added to thesolution of TiCl₃(OEt) obtained in the preceding step. The color of thesolution turned to red brown. The reaction was heated at 110° C.overnight. Crystalline solid was observed in the hot light greenishsolution, which was then cooled to room temperature. More solidcrystalized. The flask was chilled at −20° C. for 2 hours and the solidwas isolated by filtration, washed with a mixture of toluene/heptane(50/50), pentane and dried under vacuum. The yield was 37 g (99% yield)and the product was pure by ¹H and ³¹P NMR. The procedure works best byadding Ti(OEt)₄ to neat TiCl₄ or to TiCl₄ as a solution in toluene,followed by heating the mixture at 100° C. or more for a few hours. Thisgives TiCl₃(OEt) as a single product. On the other hand, if TiCl₄ isadded to Ti(OEt)₄ or if the reaction mixture is not heated to more than80° C. substantial amounts of TiCl₂(OEt)₂ or TiClx(OEt)y (where x is not3 and y is not 1) may form in addition to the desired TiCl₃(OEt)product. Indeed, it is recommended that for procedure 2, the formationof TiCl₃(OEt) is driven to completion by heat and enough reaction timebefore the addition of tBu₃P═NSiMe₃.

A person skilled in the art will immediately recognize by comparing Inv.Example 2, with Comp. Examples 1-4, that use of TiCl₃(OEt) in place ofTiCl₄ provides the desired product t-Bu₃P═N—TiCl₃ in higher yield andhigher purity and without difficult filtration steps.

Inventive Example 3

Large Scale Preparation (500 mmol) of t-Bu₃P═N—TiCl₃ from TiCl₃(OEt). Ina one liter, two necked round bottomed flask was weighed 209.65 g ofTiCl₄ (1.124 moles. 3.4% excess) and 450 mL of toluene. One of the neckswas fitted with a septum and the other one with a condenser. At the topof the condenser, a three-way nitrogen lines run from a nitrogen-vacuummanifold to the condenser and to an oil bubbler and a Na₂CO₃/watersolution bubbler. Absolute ethanol (dried with Na and distilled, 50.096g, 1.087 moles) in 25 mL of toluene was added slowly to the flask at 0°C. Fuming was observed. The addition took 20 minutes. Although thereaction between TiCl₄ and EtOH produced some HCl and caused fuming, thereaction was slow at 0° C. The reaction was heated to 50° C. andmaintained at this temperature for about 0.5 hour. Vigorous generationof HCl gas was observed. The reaction temperature was slowly increasedto 100° C. and was maintained at 100° C. overnight. A small sample ofthe orange solution was pumped to dryness under vacuum to give a whitesolid. ¹H NMR showed that there was only one ethyl environment, and sothe reaction was complete and produced only TiCl₃(OEt)). No furthergeneration of HCl gas was observed at this time. Although the solutioncould be used directly for reaction with t-Bu₃P═N—SiMe₃ in order to formt-Bu₃P═N—TiCl₃, the TiCl₃(OEt) material was isolated by removing solventunder vacuum to give pure TiCl₃(OEt). ¹H NMR, δ(toluene-d₈), 3.82 ppm,q, J=6.7 Hz, 0.83 ppm, t, J=6.7 Hz. TiCl₃(OEt) (99.65 g, 500 mmols) wasweighed into a 1 liter flask and 500 mL of toluene was added. Next,t-Bu₃P═N—SiMe₃ (144.75 g, 500 mmols) was added as solid. Fuming wasobserved indicating the Bu₃P═N—SiMe₃ contained some moisture. The fumeswere purged by nitrogen several times during the addition. The redsolution formed was stirred for 1.5 hours at room temperature and washeated to 110° C. for 21 hours. The reaction was allowed to cool toambient (room) temperature and was filtered. The solid present at thistime was collected by filtration and was washed with toluene (2×50 mL)and pentane (50 mL). The solid (183.2 g vs 185 g of theoretical yield)was almost colorless with a few slightly yellow crystals. ¹H and ³¹P NMRindicated that the product was almost pure (˜95%). This purity level issufficient to employ the product in a metallation reaction to form(C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂ (see Inv. Example 7 below). However, ifdesirable, the purity of the product could be improved by stirring withTiCl₄ (23.9 g) in 500 mL of toluene at 100° C. over a weekend. Theslurry was cooled to room temperature and was filtered. The solid overthe frit was washed with toluene (2×60 mL), pentane (2×60 mL) and wasdried by vacuum (158 g, 85% yield). ¹H and ³¹P NMR showed that theproduct t-Bu₃P═N—TiCl₃ was pure.

In view of Inv. Example 3, a person skilled in the art will immediatelyrecognize that use of TiCl₃(OEt) in place of TiCl₄ provides the desiredproduct t-Bu₃P═N—TiCl₃ in high yield and high purity at a commerciallyrelevant scale of 500 mmol.

Part B: Preparation of (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂ ComparativeExamples 5a-5e for the Preparation of 1-C₆F₅CH₂IndLi

Comp. 5a. n-BuLi (normal-butyl lithium, 1.6 M in hexanes, 4.54 mL, 7.26mmols) was added dropwise to a solution of 1-C₆F₅CH₂Indene in heptane(40 mL) at room temperature. The solution was stirred for 48 hours.Except for a very small amount of sticky material formed on the wall ofthe reaction flask, the material in the bulk solution was shown by ¹⁹FNMR to be the unreacted starting material 1-C₆F₅CH₂Indene(1-C₆F₅CH₂C₉H₇). Comp. 5b. n-BuLi (1.6 M in hexanes, 3.2 mL, 5 mmols)was added dropwise over ten minutes in a toluene solution (˜60 mL) of1-C₆F₅CH₂Indene at 0° C. The solution was stirred for 2 hours at 0° C.¹⁹F NMR showed significant amount of unreacted starting material1-C₆F₅CH₂Indene and an un-identified by-product species. Comp. 5c. Thereaction between n-BuLi and 1-C₆F₅CH₂Indene was conducted at 0° C. in1,2-dimethoxyethane for 2 hours and stirred overnight at roomtemperature. ¹H NMR showed a number of species present in the reactionmixture. Comp. 5d. n-BuLi (1.6 M in hexanes, 3.2 mL, 4 mmols) was addeddropwise at room temperature in 8 minutes to a solution of1-C₆F₅CH₂Indene (1.184 g, 4 mmols) and 1,2-dimethoxyethane (0.361 g, 4mmols) in heptane (˜40 mL). The color of the solution turned gold. Whiteprecipitate formed from the clear solution. After being stirredovernight at room temperature the slurry turned slight yellow in color.The solid was isolated by filtration, washed with pentane and driedunder vacuum. ¹⁹F NMR showed that the product 1-C₆F₅CH₂IndenylLi (i.e.[Li][1-C₆F₅CH₂indenide] or [Li][1-C₆F₅CH₂C₉H₆]) formed with about 90%purity (10% was decomposed). The reaction was repeated a few times.However, the result was not reproducible in each attempt. Comp. 5e.n-BuLi in hexanes was added to equal-molar amount of 1-C₆F₅CH₂Indene at−40° C. in THF. 1-C₆F₅CH₂IndenylLi formed quantitatively. The solutionwas warmed to 7° C. and was quenched with Me₃SiCl. The desired product1-C₆F₅CH₂-3-Me₃Si-indene formed. However, when n-BuLi in hexanes wasadded to 1-C₆F₅CH₂Indene at −10° C. in THF, severe decomposition wasobserved.

Comp. Examples 5a and 5b, show that efforts to make the1-C₆F₅CH₂Indenide anion by deprotonation with n-BuLi in the presence ofnon-polar hydrocarbon solvents such as pentane, heptane and toluene ledto no or partial reaction, or to unknown side products. Examples 5c and5d, led to reactions which produced impurities and which were difficultto reproduce. Example 5e which was conducted at low temperature (−40°C.) in THF was successful, but when higher temperatures were used (−10°C.), severe decomposition occurred.

Comparative Example 6 Preparation of (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂ fromIn Situ Generation of 1-C₆F₅CH₂IndLi in THF with n-BuLi

1-Pentafluorobenzyl indene (1-C₆F₅CH₂indene) (44.45 g, 150.2 mmol) wasdissolved in THF (500 mL) and cooled to −40° C. 1.6 M n-Butyllithium inhexanes (93.75 mL, 150.0 mmol) was added dropwise to the flask over thecourse of 2 hours to yield a dark red reaction mixture. The reaction wasstirred at −40° C. for one hour, and a cold (−40° C.) slurry oft-Bu₃PNTiCl₃ (55.59 g, 150.0 mmol) in THF (500 mL) was added dropwiseover 2 hours. After the addition, the reaction mixture was allowed towarm to room temperature overnight. In the morning, the volatiles of theorange slurry were removed in vacuo, and the reaction solids weretransferred to the glovebox, triturated with pentane, and dried invacuo. The reaction solids were then dissolved in hot (70° C.) tolueneand filtered through celite to remove the LiCl salt. The celite wasthoroughly extracted with hot toluene until the filtrate colour changedfrom orange to colourless. The volume of the filtrate was reduced invacuo, yielding a sticky orange product. This product was trituratedwith pentane and collected by filtration to yield fine orange crystals.The crude product was dried in vacuo below 200 mTorr (approximately 60g, 95.2 mmol, 63.5%). NMR spectroscopy indicated approximately 10% ofimpurities consisting of unreacted t-Bu₃PNTiCl₃ as well as theundesirable product (1-C₆F₅CH₂Ind)(t-Bu₃P═N)₂TiCl. These products couldbe extracted away from the desired product(1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂. The final product was over 95% pure by ¹HNMR (54.00 g, 85.7 mmol, 57.1%).

A person skilled in the art will realize from Comp. Example 6 (as wellas Comp. Examples 5a-5e), that due to the poor stability of thepentafluorobenzyl indenide salt obtained with n-BuLi in THF solution,that the deprotonation, and subsequent metallation reaction sequencemust be carried out at low temperature (i.e., at least −40° C.) and in acoordinating solvent such as THF to give the desired end product inreasonable yield. The use of low temperature is less desirable forreactions carried out at a commercial scale.

Inventive Example 4 Preparation of 1-C₆F₅CH₂IndLi with LDA; NMR Scale

1-C₆F₅CH₂Indene (59 mg, 0.2 mmol) and LDA (21 mg, 0.2 mmol) were weighedin a 10 mL vial in a glove box. Toluene-d₈ (˜3 mL) was added. Thecontent was shaken to mix the slurry well. ¹⁹F NMR was taken at 45 mins.Approximately 99% conversion was observed at this time. ¹⁹F NMR wastaken at 2.5 hours and 100% conversion was observed. The solution waskept at room temperature for 3 days and no change of the ¹⁹F NMRspectrum was observed. This demonstrated both the validity of using LDAas a base for the deprotonation of 1-C₆F₅CH₂Indene and the thermalstability of the product lithium indenide salt in toluene. ¹⁹F NMR,δ(toluene-d₈): −146.4 (m, 2F), −161.7 (t, 1F), −165.2 (m, 2F).

Inventive Example 5 Preparation of 1-C₆F₅CH₂IndLi with LDA; 10 mmolScale

iPr₂NLi (1.186 g, 11 mmol) was weighed into a 200 mL Schlenk flask.Toluene (˜50 mL) was added to the flask to make a slurry.1-C₆F₅CH₂Indene (3.280 g, 11 mmol) was dissolved in about 40 mL oftoluene and added into the flask. The reaction was stirred at roomtemperature for 3 hours. ¹⁹F NMR in toluene-d₈ showed that theconversion was 100%. The lithium salt need not be isolated and can beused directly in a metallation reaction.

In view of Inv. Examples 4 and 5, a person skilled in the art willrecognize that the 1-C₆F₅CH₂IndLi indenide salt is readily formed usingLDA as a base and provides a stable product. This is an improvement overdeprotonation attempts with nBuLi as shown by Comparative Examples5a-5e. Without wishing to be bound by theory, it appears that use ofrelatively unencumbered, nucleophilic base such as n-BuLi, leads todecomposition of the starting material and perhaps the reaction productas it forms, likely through nucleophilic attack of the n-Bu basedcarbanion to displace the fluorine group(s) present on the aromatic ringof the 1-C₆F₅CH₂-indene molecule. Also, use of LDA leads to therelatively coordinating molecule diisopropylamine HNiPr₂ which may helpto stabilize the desired indenide 1-C₆F₅CH₂IndLi species and to helpsolubilize the same in the reaction solvent. As a result, the synthesisof the 1-C₆F₅CH₂IndLi salt could be scaled up as shown in InventiveExample 7.

Inventive Example 6 Preparation of (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂

The 1-C₆F₅CH₂IndLi solution made in Inv. Example 5 was added to asolution of t-Bu₃PNTiCl₃ (4.103 g, 11 mmol) in toluene (50 mL) over 20minutes. The reaction mixture was stirred at room temperature overnight.A small portion of the reaction mixture was removed and pumped todryness. About 2 mL of toluene-d₈ was added to the residue to dissolvethe solid. The solution was filtered and the filtrate was used for ¹H,³¹P and ¹⁹F NMR analysis which showed that product was >98% pure. Workupof the bulk reaction mixture: The solid present was allowed to settle tothe bottom of the flask and the supernatant was passed through a glassfilter frit. The remaining solid was dissolved in CH₂Cl₂ (˜30 mL) andalso passed through a glass filter frit to remove LiCl salt. Thecombined filtrates (toluene and CH₂Cl₂) were pumped under vacuum toremove the CH₂Cl₂ and most of the toluene. During this process, theproduct began to crystallize. Solvent removal was halted and theresulting slurry was left overnight at room temperature. The productslurry was filtered through a glass filter frit and the solid wasretained and washed with a mixture of toluene and heptane (60/40) (2×20mL) and then pentane (20 mL). The product (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂was a bright orange-yellow crystalline solid. The yield was 6.09 g(94%). ¹H, ¹⁹F and ³¹P NMR analysis showed that the product was pure.¹⁹F NMR, δ(toluene-d₈): 145.2 (dd, 2F), 159.5 (dd, 1F), 164.5 (m, 2F).³¹P NMR, δ(toluene-d₈): 45.8 (s). ¹H NMR, δ(toluene-d₈): 7.96 (m, 1H),7.60 (m, 1H), 7.16 (m, 2H), 6.88 (m, 1H), 6.50 (m, 1H), 4.57 (d, J=14Hz, 1H), 4.08 (d, J=14 Hz), 2.14 (s, 3H), 1.20 (d, J=14 Hz, 27H).

Inventive Example 7 Preparation of (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂ at aLarge Scale (ca. 400 mmol)

In-situ LDA Synthesis: iPr₂NH (42.776 g, 423 mmol) was weighed in a 2 Lround bottomed flask and 300 mL of toluene was added. N-BuLi (251.16 mL,1.6 M, 402 mmols) was added slowly to the toluene solution of iPr₂NHthrough a dropping funnel over 70 min. The temperature of the solutionincreased from 25° C. to 43° C. The mixture was stirred for another 0.5hour to complete the formation of iPr₂NLi. Deprotonation:1-C₆F₅CH₂Indene (119.086 g, 402 mmols) was weighed into a 2 L roundbottomed flask and 300 mL of toluene was added. The iPr₂NLi solutionmade in the previous step was poured into the 1-C₆F₅CH₂Indene solutionwhile monitoring the temperature. The temperature of the reactionmixture reached 40.7° C. following the addition of LDA and the mixturewas stirred for another 1.5 hours. A slurry formed due to the formationof solid 1-C₆F₅CH₂IndLi. ¹⁹F NMR (with THF-d₈ as solvent) indicated thatthe reaction was complete. This reaction mixture was used directly inthe next step. Metallation: tBu₃PNTiCl₃ (148.912 g, 402 mmol), preparedas above in Inventive Example 3, was pre-weighed and transferred to a 3L round bottomed flask. Toluene (500 mL) was added to make a slurry. The1-C₆F₅CH₂IndLi solution from the last step was added through a cannulato the t-Bu₃PNTiCl₃ slurry over 10 minutes. The color of the reactionbecame bright orange. The temperature of the reaction mixture reached40.7° C. after the addition of the indenide salt. The reaction mixturewas then stirred overnight, and then left to stand without stirring for3 hours. Next, the supernatant, which contained some suspended LiCl wasdecanted off. The remaining yellow solid was dissolved in about 500 mLof dichloromethane. This solution was filtered through at least 2 inchesof compact celite on a glass filter frit and the celite was rinsedseveral times with dichloromethane. The filtrate was pumped to drynessyielding the product (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂ as crystalline solid.The product solid was washed with pentane (3×100 mL) and dried to 250mTorr to give pure (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂. The weight of thesolid was 256.50 g. Meanwhile, the supernatant (with suspended withLiCl) was filtered through at least 2 inches of compact celite on aglass filter frit and the celite was thoroughly rinsed with toluene. Thefiltrate was pumped to about 20 mL and the product precipitated out ofsolution. The suspension was filtered and the solid retained was rinsedwith toluene (2×20 mL), pentane (2×20 mL) and dried under vacuum. Thesolid product weighed 11 g. The combined yield was 256.50 g+11 g=257.5 gof (1-C₆F₅CH₂Ind)(t-Bu₃P═N)TiCl₂, 92% yield and the product was pure.¹⁹F NMR, δ(THF-d₈): 145.6 (m, 2F), 160.0 (m, 1F), 166.4 (m, 2F). ³¹PNMR, δ(THF-d₈): 46.0 (s). ¹H NMR, δ(THF-d₈): 7.69 (m, 1H), 7.48 (m, 1H),7.1-7.25 (m, 2H), 6.91 (m, 1H), 6.52 (m, 1H), 4.57 (d, J=14 Hz, 1H),4.20 (d, J=14 Hz), 2.31 (s, 3H), 1.58 (d, J=14 Hz, 27H).

A person skilled in the art will recognize that the below reactionsequence can be carried out at moderate temperatures, in a singlesolvent and at large scale (at least 400 mmol) to provide the desiredproduct in high overall yield and purity.

The present invention has been described with reference to certaindetails of particular embodiments thereof. It is not intended that suchdetails be regarded as limitations upon the scope of the inventionexcept insofar as and to the extent that they are included in theaccompanying claims.

What is claimed is:
 1. A method for making R¹ ₃P═N—TiCl₃, said methodcomprising combining TiCl₃(OR) with an approximately equimolar amount ofR¹ ₃P═N—SiMe₃ in the presence of a solvent, to give as reaction productsthe R¹ ₃P═N—TiCl₃ and RO—SiMe₃ wherein R¹ is independently selected froma C₁₋₃₀ hydrocarbyl radical which is unsubstituted or furthersubstituted by one or more halogen atom, a C₁₋₈ alkoxy radical, a C₆₋₁₀aryl radical, a C₆₋₁₀ aryloxy radical, an amido radical, a silylradical, and a germanyl radical; and wherein R is a primary, secondaryor tertiary alkyl group or an aromatic group.
 2. The method of claim 1,wherein the TiCl₃(OR) is generated by combining TiCl₄ with anapproximately equimolar amount of ROH.
 3. The method of claim 2 whereinthe TiCl₃(OR) is generated by adding ROH to TiCl₄.
 4. The method ofclaim 1, wherein the TiCl₃(OR) is generated by combining TiCl₄ withTi(OR)₄ in a molar ratio of approximately 3:1.
 5. The method of claim 4wherein the TiCl₃(OR) is generated by adding Ti(OR)₄ to TiCl₄.
 6. Themethod of claim 1 wherein each R¹ is a C₁₋₂₀ alkyl radical, a C₁₋₈alkoxy radical, a C₆₋₁₀ aryl radical, a C₆₋₁₀ aryloxy radical, an amidoradical, a silyl radical, and a germanyl radical.
 7. The method of claim1 wherein each R¹ is a C₁₋₂₀ alkyl radical.
 8. The method of claim 1wherein each R¹ is selected from propyl, butyl, pentyl, hexyl and octyl.9. The method of claim 1 wherein each R¹ is a tert-butyl group.
 10. Themethod of claim 1 wherein R is a primary or secondary alkyl group. 11.The method of claim 1 wherein R is a primary alkyl group.
 12. The methodof claim 1 wherein R is methyl, ethyl, propyl, butyl, or pentyl.
 13. Themethod of claim 1 wherein R is methyl, ethyl, n-propyl, n-butyl,iso-propyl, sec-butyl, or neo-pentyl.
 14. The method of claim 1 whereinR is methyl, ethyl or iso-propyl.
 15. The method of claim 1 wherein R ismethyl.
 16. The method of claim 1 wherein R is ethyl.
 17. The method ofclaim 1 wherein R is isopropyl.
 18. The method of claim 1, wherein thesolvent is a hydrocarbon solvent.
 19. The method of claim 1, wherein thesolvent is a hydrocarbon solvent and the R¹ ₃P═N—SiMe₃ is added to theTiCl₃(OR).
 20. A method for making (1-R²-Indenyl)Ti(N═PR¹ ₃)Cl₂comprising the following steps: i) combining TiCl₃(OR) with anapproximately equimolar amount of R¹ ₃P═N—SiMe₃ to give R¹ ₃P═N—TiCl₃;ii) combining a 1-substituted indene 1-R²—C₉H₇ with an approximatelyequimolar amount of lithium di-isopropylamide to give a 1-substitutedindenide 1-R²—C₉H₆ anion; iii) combining the 1-substituted indenide1-R²—C₉H₆ anion with the R¹ ₃P═N—TiCl₃ to give (1-R²-Indenyl)Ti(N═PR¹₃)Cl₂; wherein R¹ is independently selected from a C₁₋₃₀ hydrocarbylradical which is unsubstituted or further substituted by one or morehalogen atom, a C₁₋₈ alkoxy radical, a C₆₋₁₀ aryl radical, a C₆₋₁₀aryloxy radical, an amido radical, a silyl radical, and a germanylradical; R is a primary, secondary or tertiary alkyl group or anaromatic group; and R² is a substituted or unsubstituted alkyl group, asubstituted or unsubstituted aryl group, or a substituted or anunsubstituted benzyl group.
 21. The method of claim 20 wherein each R¹is a C₁₋₂₀ alkyl radical, a C₁₋₈ alkoxy radical, a C₆₋₁₀ aryl radical, aC₆₋₁₀ aryloxy radical, an amido radical, a silyl radical, and a germanylradical.
 22. The method of claim 20 wherein each R¹ is a C₁₋₂₀ alkylradical.
 23. The method of claim 20 wherein each R¹ is selected frompropyl, butyl, pentyl, hexyl and octyl.
 24. The method of claim 20wherein each R¹ is tertiary butyl group (t-Bu).
 25. The method of claim20 wherein R² is an alkyl group, an aryl group, or a benzyl group,wherein each alkyl, aryl and benzyl are optionally further substitutedwith groups selected from alkyl groups, aryl groups, alkoxy groups,aryloxy groups, alkylaryl groups, arylalkyl groups and halide groups.26. The method of claim 20 wherein R² is a benzyl group which isunsubstituted or substituted with at least one fluoride atom.
 27. Themethod of claim 20 wherein R² is a pentafluorobenzyl group (C₆F₅CH₂—).28. The method of claim 20 wherein R is a primary alkyl group or asecondary alkyl group.
 29. The method of claim 20 wherein R is a primaryalkyl group.
 30. The method of claim 20 wherein R is methyl, ethyl,propyl, butyl, or pentyl.
 31. The method of claim 20 wherein R ismethyl, ethyl, n-propyl, n-butyl, iso-propyl, sec-butyl, or neo-pentyl.32. The method of claim 20 wherein R is methyl, ethyl or iso-propyl. 33.The method of claim 20 wherein R is methyl.
 34. The method of claim 20wherein R is ethyl.
 35. The method of claim 20 wherein R is isopropyl.